Sheet material



FIG. 1 depicts a first embodiment of the design; and,

FIG. 2 depicts a second embodiment of the design.

In both views, the sheet material has been shown broken away on all sides to indicate that the claimed design has indeterminate length and width, and it is understood that the pattern upon the sheet material repeats indefinitely throughout the entire surface of the sheet material. 

The ornamental design for sheet material, as shown and described. 